Speed change gearing



Dec. 15, 1953 A. MASCHERPA 2,662,417

SPEED CHANGE GEARING Filed May 1, 1951 3 Sheets-Sheet l lnvenfor Bfnzonza vfl/a'schey jaco Dec. 15, 1953 A. MASCHERPA SPEED CHANGE GEARING 3 Shets-Sheet 2 Filed May 1 1951 Invvzfir w flas charm Dec. 15, 1953 A. MASCHERPA SPEED CHANGE GEARING 3 Sheets-Sheet 15 Filed May 1 1951 In 2721?? ifasckerpa m W Patented Dec. 15, 1953 UNITED STATES PATENT OFFICE SPEED CHANGE GEARING Antonio Mascherpa, Novara, Italy Application May 1, 1951, Serial No. 223,902

Claims priority, application Italy May 17, 1950 4 Claims. (Cl. 74-352) In certain machine tools it is necessary to efthe gear cone without requiring an opening in r the box of the mechanism.

Another object of this invention is to provide a mechanism of the indicated character with a single control lever and to limit the operation to a single movement of the lever when shifting from one drive ratio into another.

Other objects and advantages of the invention are that it meets the requirements for effectual and efiicient stepped gear drives with a wide range of speeds on the output shaft; and to provide a change speed motion transmission mechanism of simplified construction, and in general, to improve the efficiency and convenience of operation.

In the accompanying drawings.

In Fig. 1 is diagrammatically shown the change mechanism, while in Figs. 2, 3, 4, and 6 are shown the various sections and the elements of the said change; and Figs. '7, 8, 9 and show the four different positions of the same elements.

The input movement of the shaft II is imparted at A, which rotates the gear [2 and, by way of the laterally movable, and rotatably driven gear it, the movement is transmitted to any one of the gears of the column l5 and leaves at B.

The mechanism of the displacement for the gear M for the change of speed takes place as follows: the lever l is rotated by handling the knob 2.

On rotating the lever l, which is rigid with the shaft 4, the hub 5 is rotated, which carries on one side an eccentric pin 1 and on the other side an eccentric pin 6, which pins respectively have eccentricities El and E2.

If the lever l is in the normal working position, the hub 5 is in the position in which the two eccentrics are on the vertical (Fig. '7), the eccentric I at top, the eccenrtic 6 at bottom. If the lever l is rotated 135, and hub 5 is rotated likewise, the pin 6 by reason of the eccentricity El lifts the rod 8 a determined amount, which rod 8 by means of the pin 9, oscillates the rocker l0 about the axis A of the shaft I l on which the fork l3 can slide longitudinally to shift the rotor gear l2 and the gear l4. Said fork has an extension provided with a pin it, which fits into a profiled groove l'i, provided in the base of the aforesaid rocker Hi.

If the rocker ii], by reason of the vertical movement of the rod 8 rotates angularly about the axis A, the fork is turns angularly, taking the planetary gear 16 away from the meshing position.

By reason of said rotation of the lever I, the pin enters a groove of the Maltese cross I8 (Fig. '7). If now the angular rotation of the lover I is carried on by further the pin 1 rotates the Maltese cross by 90 (Figs. 9 and 10) The rotation of the Maltese cross and of the gear is rigid therewith, rotates the gear 28, which is loose on the shaft ii and by means of the intermediaries 2| causes displacement of the rack 22 by a determined amount corresponding to the distance between one gear and the other on the column !5.

The rack 22 is rigid with a hub 23 having a groove 24, in which is fitted slidably the extension 25 of the fork 53. In that way, the longitudinal displacement of the rack causes the longitudinal displacement of the fork l3 and, therefore, of the grive gear l2 and of its gear [4.

lhe gears 12 and it each are shifted into a position to mesh with the next immediate gear to the right or to the left of the one, with which they meshed previously: to the right if the handle was rotated in one direction, to the left if the handle was rotated in the other direction.

On rotating the lever l on by a further the pin 6 takes the rod 8 back to its original position and, therefore, moves the gear it to mesh with the gear in the column l5.

It is evident that the meshing position, which the planetary gear must assume progressively as it displaces itself in front of the new gear, depends on the particularly diameter of that gear and, therefore, on the ratios to be obtained with with the change.

In order to obtain those various meshing positions, the rocker it has a groove ll, which possesses steps provided in relationship to the various diameters of the various gears.

The consequence is, that as the fork l3 and thus the gear [4 are displaced longitudinally, the angular position thereof is corrected and varied by the position that is being assumed by the pin it in the various steps of the groove [1.

Rigid with the gear 2% there is a disc 26, turns an amount proportional to the ratio between the gears l9 and 26. Consequently, each turn of the lever I causes the rotation of the disc 28 by a certain amount. Said disc is numbered to indicate, with respect to the pointer 21, the new position attained by the gear l4 and, therefore, to mark the speed ratio attained.

To summarize, it may be said that in the move ment of the lever I 360, the following operations are performed:

(a) Inthe first 135 the rocker H] and the fork l3 as well take the gear 14 away from the meshing position;

(b) In the subsequent 90 the gear M is shifted longitudinally one position;

In the further rotation 135, the gear '14 is taken back to the meshing position.

The groove [1 gives the increment of angular rotation positive or negative "forthe passage from one particular diameter to another one of the column and, therefore, for the actual meshmg.

The disk 26 marks the meshing position obtained and, therefore, the change ratio.

Itcan be thus clearly seen that for each turn of the lever I, the gear 14' is shifted into one position or another according to the number of turns performed.

It is possible to turn in the right direction as well as in the left direction. Moreover, themechanism has characteristics of semi-automaticity and self-warranted safety, because it is impossible to displace the gear M longitudinally before taking it away from the meshing position and it is also impossible to have the gear E4 mesh again if it has not reached its new position.

Moreover, the position obtained is clearly indicated externally. The embodiment of such a mechanism permits use of a box for the change whatmanner the same is to be performed, I

declare that-what I claim is:

1.- In a shifting mechanism for stepped gear drives, particularly for machine tools, the combination of a driving shaft, a driving gear slidable on said shaft and having a splined section, a member slidable and oscillatable on said shaft coupled with said splined section, a driven gear mounted on said member andmeshing with said ,driving gear, arr-output shaft with a stepped gear cone on it, the range of oscillation and slide of said member bringing in contact said driven gear with any gear of said cone, a rocking mem- :ber guiding the oscillatory motion of said first member, a rack slidable in the direction of said driving shaft provided with extensions meshing with said fii'stmember to guide its movement, a

rotatable control spindle, means to transform the rotation of said spindle in an alternative swinging of said rocking member, and means operated-by the spindle causing theintermittent operation of the rack.

' 2; In' a shifting mechanism for stepped gear drives, particularly for machine tools, the com- :bination of a driving shaft, a drivinggear slidable on said shaft and having asplined-section,

a member slidable and. oscillatable on said shaft coupled with said splined section, a driven gear mounted on said memberand meshing'with said zdriving gear, an output shaft with a stepped gear .c'one on it, the range of oscillation andaslide "of said member bringing in contact said' driven gear with any gear ofsaid'cone, a rocking mema: pin on said cam, a rod engaging said pin and said rocking member to transform circular motion *of said cam into oscillating motion of said rocking member.

3. In a shifting mechanism for stepped gear drives, particularly for machine tools, the combination ofv adriving shaft, a driving gear slidable on said shaft and having a splined section, a'm'ember slidable and oscillatable on said shaft coupled with said splined section, a driven gear mounted on said member and meshing with said driving gear, an output shaft with a stepped gear cone on it, the range of oscillation and slide of said member bringing in contact said driven gear with any gear of said cone, a rocking member guiding the oscillatory motion of said first member, a rack slidable in the direction of said driving shaft provided with extensions meshing with said first member to guide its movement, a rotatable control spindle, a cam on said spindle, a pin on said cam, a rod engaging said pin and said rocking member, a second pin on same cam, a Maltese cross engaging said pin and driven thereby in intermittent rotation, atrain of gears for transmitting said lastflmotion ,to said rack, which guides said first member andsaid driving gear in the direction'determined by the direction of rotation of said Maltese cross.

4. In a shifting mechanism for stepped gear drives, particularly for machine tools, the combination of a driving shaft, a driving gear slidable on said shaft andhaving a splined section, a member slidable and oscillatable on said shaft coupled with said splined section, a driven gear mounted on said member andmeshing with said driving. gear, an output shaft with a stepped gear cone on it, the range of oscillation and slide of said member bringing in contact said driven gear with any gear of said cone, a rocking member guiding the oscillatory motion'o'f said first member, a rack slidable in the direction of said driving shaft provided with extensions .meshing with said first member to. guide its movement, a rotatable control spindle, a cam on said spindle, a pin on said earn, a rod engaging said pin and said rocking member, a second pin on same camya Maltese cross engaging said pin and driven thereby in intermittent rotation,

*a train of gears for transmitting said last motion-to said rack, said rocking member having a slot in which is movable a roll pivotally engaged with said first slidable and oscillatable member, said slot being shaped so that said driven gear can mesh with any one of the gears of said stepped cone in their reciprocal correct position.

ANTONIO MASCHERPA.

References-Cited in the file of this patent UNITED STATES PATENTS Number 7 'Name' Date 1,002,455 Ros'en'stein Sept; 5, "1911 1,084,084 Guerra Jan. '13, 1914 1,753,187 Grout Apr: 1, 1930 2,297,422 'Mobius-et-al. Sebtg29, 1942 2,377,305 'Bickel June 5,"1945 2,485,151 Gorrell Oct. '18, 1949 FOREIGN PATENTS "Number Country r-D'ate 360,627 Germany Oct." 5, 1922 

